The present invention is directed generally to a printed sheet monitoring assembly. More particularly, the present invention is directed to a printed sheet monitoring assembly for controlling printed sheets. Most specifically, the present invention is directed to a printed sheet monitoring assembly for controlling printed sheets in a sheet fed rotary press. The printed sheets are transferred by spaced gripper bars which extend between two parallel endless chains. A suction box is used to pull the printed sheets tightly against a surface of the suction box. While each individual sheet is so situated, it can be checked by a CCD line or area array image sensor which is placed below the suction box so as to not be obstructed by the parallel endless gripper chains.
The opto-electronic device, such as a CCD line or area array image sensor requires a clear, unobstructed view of the sheet or sheets whose quality is being evaluated. The use of sheet grippers and endless gripper chains presents problems since the opto-electronic sheet quality inspecting sensor will be disrupted by the pressure of the sheet grippers or endless gripper chains in its field of scan.
A need exists for a printed sheet monitoring assembly which will provide for the accurate, automatic scanning and monitoring of printed sheets. The printed sheet monitoring assembly in accordance with the present invention provides such a device and is a significant improvement over prior art devices.